smtp.netscalibur.it has no CNAME records.
Question and response
Question
dig smtp.netscalibur.it. NS
Answer
The response has no answer records.
Authority
netscalibur.it. 10800 SOA ns1mi.infracom.it. sistemi.infracom.it. 2022071401 7200 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0